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Position of the first n-digit prime occurring in the decimal expansion of e.
2

%I #10 Jul 22 2020 11:39:24

%S 1,2,1,15,25,13,1,65,20,100,38,54,8,48,40,41,9,83,152,19,52,6,16,66,4,

%T 4,69,25,28,7,97,174,4,48,127,11,40,58,48,69,45,40,34,119,6,7,92,61,2,

%U 40,138,105,332,28,70,322,62,231,78,339,245,66,49,439,298

%N Position of the first n-digit prime occurring in the decimal expansion of e.

%C Leading zeros are not allowed.

%H Harvey P. Dale, <a href="/A272304/b272304.txt">Table of n, a(n) for n = 1..200</a>

%e a(1) = 1 because the initial digit "2" of e is prime.

%t With[{ed = RealDigits[E, 10, 10000][[1]]}, Table[Position[Partition[ed, n, 1], _?(PrimeQ[FromDigits[#]] && #[[1]] != 0 &), {1}, 1, Heads -> False], {n, 100}]] // Flatten

%Y Cf. A001113, A198344.

%K nonn,base

%O 1,2

%A _Harvey P. Dale_, Apr 25 2016